Ok, so I havent done a hell of a lot to my truck yet. It is 87 2wd, 22r, former 4 speed converted to 5 speed (not sure how to tell which 5 speed it is), and G662 rear. I wheeled and painted the rusted floorboards to stave them off for now, but theyll need new metal. The frame is perfect and the rest of the body is ok for an 87. This truck was intended to be my daily driver for years to come and Im currently looking to squeeze mileage and longevity out of it. It runs superbly right now. The carb and choke work better than when I got it and I calculated its getting 27mpg avg on my trips to work and back on premium (Started getting premium because it only costs me like $2.50 extra per tank). The roads there are 55mph or less, I coast to stop signs, I take off in 2nd, there are no hills to coast down while shut off and bumpstart. I was wondering a few things:
1. How do I tell what tranny I have?

2. Is there an advantage to the Weber carbs? My factory carb is doing phenomenally.

3. What is the tire size everyone is using on a stock ride height 2wd? Pressure? Im running 40psi in 44psi max tires currently.

If I could get into the 30s with this truck, Id be very happy. It appears I have the relative setup to do it, I just need some suggestions. Im not trying terribly hard here to get 27. Im just using low shift points and coasting when I can. Any thoughts?